The invention relates to processes for producing fibers from synthetic polymer, and more particularly, it relates to monitoring these processes to provide positional control of polymer throughput.
In the past, it has been a common practice to provide power, to polymer or solution spin pumps on spinning machine positions, at a drive frequency and voltage required to produce the desired throughput and fiber denier. Many pumps have been driven by a single drive for product consistency, uniformity, and simplicity. During time periods when fiber production has been interrupted, as a result of process breaks or positional maintenance, spin pumps have continued to operate at full throughput causing a loss of ingredients and production of excessive waste. Alternatively, spin pumps can be shut down completely for breaks or maintenance but experience has shown that shutting down positional spin pumps for substantial periods of time can lead to excessive costs related to loss of spin pack, freezing of polymer in transferlines, and general degradation and loss of control of polymer quality. Furthermore, when a pump which has been shut down is restarted, the polymer temperature and quality is off standard for a time related to the length of the shutdown. In addition, when a number of spinning positions of a multiposition machine are shut down simultaneously, the flow of polymer through the common manifold supplying the positions which are still operating is slowed to a point at which the chemical and/or physical properties of the product from the operating positions may be affected, or the polymer supply system can be adversely affected in other ways.